The technology described in this disclosure relates generally to semiconductor devices and more particularly to fabrication of semiconductor devices.
Traditional planar devices often encounter various problems, such as short-channel effects and poor sub-threshold characteristics, as feature sizes of the devices continue to shrink. Non-planar devices, such as FinFETs, have become more and more popular to improve device performance and increase packing densities in devices and circuits. A FinFET usually includes semiconductor fin structure formed vertically on a substrate. A gate structure is formed over and along the sides of the fin structure to produce faster, more reliable and better-controlled devices.